Methods and compositions for the improvement of skeletal muscle function in a mammal

Abstract

The present invention is directed to the treatment of muscular dysfunction or increasing muscle strength and / or decreasing muscle fatigue in a subject using a composition that includes a biguanide or a pharmaceutically acceptable salt thereof, e.g., at a low dosage.

Description

STATEMENT AS TO FEDERALLY SPONSORED RESEARCH

[0001] This invention was made with government support under grant number NIH R44 NS059098. The government has certain rights in the invention.BACKGROUND OF THE INVENTION

[0002] In general, the invention relates to methods of using a biguanide to treat muscular dysfunction, increase muscle strength, and / or reduce muscle fatigue. The invention also features pharmaceutical compositions formulated with low dosages of a biguanide.

[0003] Progressive skeletal muscle weakness and fatigue accompany numerous human diseases and disorders including, e.g., cancer, acquired immune deficiency syndrome (AIDS), advanced organ failure (e.g., heart, liver, and kidney failure), chronic obstructive pulmonary disease (COPD), immobilization or disuse atrophy, burns, incontinence, sepsis, aging, and neuromuscular diseases (e.g., muscular dystrophies). Certain therapies may slow or reverse a decline in muscle mass or function including, e.g., hormonal interventions, ...

Examples

example 1

Metformin Increases Strength and Reduces the Fatigue Rate of Mouse Skeletal Muscle Tissue from a Genetic Model of Duchenne Muscular Dystrophy

[0115]Conditionally immortalized skeletal muscle cells from the mdx mouse muscle (Morgan et al., Dev Biol. 162: 486-498, 1994) were tissue engineered into contractile muscle tissue (mBAMs), as described herein. (See also, e.g., Vandenburgh et al., Muscle and Nerve 37: 438-447, 2008; Vandenburgh et al., Treat NMD Meeting, 2009). Briefly, several hundred thousand proliferating myoblasts were mixed with a solution of extracellular matrix (collagen or fibrin) and pipetted into custom wells containing two flexible “posts” (FIG. 1A). The cell / matrix mixture gelled around the tops of the posts, forming a defined tubular structure (FIG. 1B). The myoblasts differentiated into several hundred organized contractile muscle fibers (called miniature BioArtificial Muscle (mBAM); FIG. 1C) in tissue culture medium, such as that described in Vandenburgh et al., ...

example 2

Biguanides Increase Skeletal Muscle Strength and Decrease the Rate of Muscle Fatigue of Normal Mouse Skeletal Muscle Tissue

[0118]Skeletal muscle cells from the leg muscles of normal mice were isolated by standard tissue culture protocols (Rando et al., J Cell Biol. 125: 1275-1287, 1994), tissue engineered into contractile muscle tissue (mBAMs), and muscle force and fatigue measured as described in Example 1 (above).

[0119]High glucose tissue culture medium (4.5 g / l) was used in all experiments to maintain glucose levels well above normal human blood plasma levels (0.9 to 1.8 g / l) and, thereby, minimize drug action through increased glucose availability to the muscle cells. On Days 6-8 post-casting, metformin, phenformin (Fluka Cat. No. P7045-1G), or proguanil (Ipca Laboratories, CAS No. 637-32-1, Batch No. 8001HPRI) at different concentrations were added to the tissue culture medium, and maximal tetanic force was measured 24 hours later in a MFAS™. Every 24 hours, fresh metformin, ph...

example 3

Biguanides Increase Skeletal Muscle Strength and Reduce the Rate of Muscle Fatigue of Normal Human Muscle Tissue

[0123]Skeletal muscle cells from the vastus lateralis muscle of human volunteers were isolated by thin needle muscle biopsy and grown by standard tissue culture protocols (Shansky et al., “Tissue engineering human skeletal muscle for clinical applications” in Culture of Cells for Tissue Engineering (G. Vunjak and I. Freshney, eds.), pages 239-257, 2006), tissue engineered into contractile muscle tissue (mBAMs), and muscle force and fatigue measured as described in Example 1. On Days 7-10 post-casting, metformin, phenformin, buformin, or proguanil at different concentrations were added to the tissue culture medium and maximal tetanic force measured 24 hours later in MFAS™. High glucose tissue culture medium (4.5 g / l) was used to maintain glucose levels well above normal human blood plasma levels (0.9 to 1.8 g / l) and, thereby, minimize drug action through increased glucose a...

STATEMENT AS TO FEDERALLY SPONSORED RESEARCH

[0001] This invention was made with government support under grant number NIH R44 NS059098. The government has certain rights in the invention.BACKGROUND OF THE INVENTION

[0002] In general, the invention relates to methods of using a biguanide to treat muscular dysfunction, increase muscle strength, and / or reduce muscle fatigue. The invention also features pharmaceutical compositions formulated with low dosages of a biguanide.

[0003] Progressive skeletal muscle weakness and fatigue accompany numerous human diseases and disorders including, e.g., cancer, acquired immune deficiency syndrome (AIDS), advanced organ failure (e.g., heart, liver, and kidney failure), chronic obstructive pulmonary disease (COPD), immobilization or disuse atrophy, burns, incontinence, sepsis, aging, and neuromuscular diseases (e.g., muscular dystrophies). Certain therapies may slow or reverse a decline in muscle mass or function including, e.g., hormonal interventions, ...

Examples

example 1

Metformin Increases Strength and Reduces the Fatigue Rate of Mouse Skeletal Muscle Tissue from a Genetic Model of Duchenne Muscular Dystrophy

[0115]Conditionally immortalized skeletal muscle cells from the mdx mouse muscle (Morgan et al., Dev Biol. 162: 486-498, 1994) were tissue engineered into contractile muscle tissue (mBAMs), as described herein. (See also, e.g., Vandenburgh et al., Muscle and Nerve 37: 438-447, 2008; Vandenburgh et al., Treat NMD Meeting, 2009). Briefly, several hundred thousand proliferating myoblasts were mixed with a solution of extracellular matrix (collagen or fibrin) and pipetted into custom wells containing two flexible “posts” (FIG. 1A). The cell / matrix mixture gelled around the tops of the posts, forming a defined tubular structure (FIG. 1B). The myoblasts differentiated into several hundred organized contractile muscle fibers (called miniature BioArtificial Muscle (mBAM); FIG. 1C) in tissue culture medium, such as that described in Vandenburgh et al., ...

example 2

Biguanides Increase Skeletal Muscle Strength and Decrease the Rate of Muscle Fatigue of Normal Mouse Skeletal Muscle Tissue

[0118]Skeletal muscle cells from the leg muscles of normal mice were isolated by standard tissue culture protocols (Rando et al., J Cell Biol. 125: 1275-1287, 1994), tissue engineered into contractile muscle tissue (mBAMs), and muscle force and fatigue measured as described in Example 1 (above).

[0119]High glucose tissue culture medium (4.5 g / l) was used in all experiments to maintain glucose levels well above normal human blood plasma levels (0.9 to 1.8 g / l) and, thereby, minimize drug action through increased glucose availability to the muscle cells. On Days 6-8 post-casting, metformin, phenformin (Fluka Cat. No. P7045-1G), or proguanil (Ipca Laboratories, CAS No. 637-32-1, Batch No. 8001HPRI) at different concentrations were added to the tissue culture medium, and maximal tetanic force was measured 24 hours later in a MFAS™. Every 24 hours, fresh metformin, ph...

example 3

Biguanides Increase Skeletal Muscle Strength and Reduce the Rate of Muscle Fatigue of Normal Human Muscle Tissue

[0123]Skeletal muscle cells from the vastus lateralis muscle of human volunteers were isolated by thin needle muscle biopsy and grown by standard tissue culture protocols (Shansky et al., “Tissue engineering human skeletal muscle for clinical applications” in Culture of Cells for Tissue Engineering (G. Vunjak and I. Freshney, eds.), pages 239-257, 2006), tissue engineered into contractile muscle tissue (mBAMs), and muscle force and fatigue measured as described in Example 1. On Days 7-10 post-casting, metformin, phenformin, buformin, or proguanil at different concentrations were added to the tissue culture medium and maximal tetanic force measured 24 hours later in MFAS™. High glucose tissue culture medium (4.5 g / l) was used to maintain glucose levels well above normal human blood plasma levels (0.9 to 1.8 g / l) and, thereby, minimize drug action through increased glucose a...

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